This invention relates to a pressure-sensitive tape containing nitroglycerin (NTG) in the adhesive portion of the tape, and to a method of treating angina and/or controlling hypertension and/or treating congestive heart failure.
Nitroglycerin is a known drug sold for the treatment of angina, particularly prophylactic treatment of angina.
Numerous formulations which provide nitroglycerin for delivery to and through the skin are known. In general these formulations require complex reservoir and sustained release systems. Many require several different layers.
Inclusion of nitroglycerin in solution in the adhesive portion of a pressure-sensitive adhesive tape is known. One such tape system is that described in EPO laid open application No. 062682. This application discloses adhesive copolymers of dodecyl methacrylate with one or more monomers such as acrylamide or acrylic acid. The EPO application states that adhesive copolymers of alkyl acrylates or alkyl methacrylates in which the alkyl group contains 4-12 carbon atoms have a high ability to absorb nitroglycerin and therefore do not release sufficient amounts of nitroglycerin to skin. Hence, the invention set forth in the EPO application relates to the apparent finding that adhesives prepared from dodecyl methacrylate provide formulations with improved release of nitroglycerin from the adhesive layer. The adhesive layer of the prior art tape additionally may contain what are termed "softeners", which are said to improve adhesion to skin and control the retention and release of nitroglycerin. Examples of such softeners are long chain fatty acid esters such as isopropyl myristate, and fatty acid monoglycerides such a glycerol monostearate. Nitroglycerin is included in the adhesive in the amount of 1-20 mg per 100 cm.sup.2 of the tape. Several of the Examples of this application specify adhesive formulations which contain nitroglycerin in an amount of 2% by weight based on the weight of the adhesive copolymer.
U.S. Pat. No. 3,742,951 discloses a nitroglycerin transdermal tape which comprises nitroglycerin contained in a discrete reservoir layer or microcapsules. A transporting aid such as aliphatic esters is also disclosed as being useful.
U.S. Pat. No. 4,485,087 discloses a transdermal tape which comprises a backing and an adhesive layer which may contain a variety of medicaments including nitroglycerin. The backing is one which allows the medicament to migrate therethrough so as to function as a reservoir for the medicament. In making the transdermal tape, the medicament is added to the adhesive in a concentration higher than the solubility of the medicament in the adhesive, and excess medicament is said to migrate into the backing. A variety of adhesives are disclosed including acrylic adhesives.
The use of glyceryl monolaurate as a penetration enhancer for transdermal administration of medicaments has been suggested previously.
Isopropyl myristate is a known penetration enhancer for transdermal administration of medicaments.